Best ways of treating and controlling powdery mildew

Powdery mildew

As name suggests it is a fungus (mildew) caused plant disease in which plant parts like leaves, stems, flowers and buds are covered with a powder like substance. The powdery substance is nothing but numerous spores of fungus produced in high humidity and moderate temperature environment.

Powdery mildew is common problem of plants like rose, zinnia, and lilacs. It also affects some vegetables – sweet peas, gourds, melon, and onion and grapes plant.

Symptoms

Powdery mildew attacks lower plant parts (bottom leaves) first which are just above the ground, then it move upwards affecting upper leaves, stem, buds and flowers. White spots start developing on affected leaves which keep enlarging with time. Leaves become colorless and fall off ultimately.

However, plant doesn’t die on attack of powdery mildew but it weakens and produces less number of blooms and fruits. In ornamental plants, it could affect look of the plant by destroying foliage. 

Reasons of infection

On favorable conditions of high humidity and moderate temperature fungus reproduces quickly and generates large number of spores.  Spores spread with wind and affect nearby plants. 

Control and Treatment

Powdery mildew can’t be cured but it can be prevented and treated in following ways.

- Take out infected leaves or plant in case of small level infection and put them separately in a plastic bag. It would help in stopping infection to nearby growing plants and vegetables. Compost bag material if you want.

- Make sure that plants are having proper aeration and getting enough direct sun light as it inhibits spore germination.

- Spray milk diluted with water (1: 10) on susceptible plants. Repeat the application to eliminate the disease.

Mix 1 tablespoon baking soda with normal water and spray on affected parts. Add few drops of liquid soap in it.

- Garlic extract is a good and cost effective way of controlling powdery mildew. It can be made by blending two garlic in 1 liter water with few drops of liquid soaps. Strain the mixture through a cloth to remove the solid part and spray the liquid on the plant.  

- Spray plant with neem oil made by seeds. Neem oil has fungicidal properties. It disrupts fungus metabolism, forms a barrier between the plant and the fungus and inhibit spore germination. On application it is absorbed by the leaf and circulated around to maximize area of coverage. Neem oil mixed in water, absorbed by the roots and circulated all over the plant.

- Use sulfur sprays available in market to control powdery mildew as sulfur creates low pH environment which is detrimental for the fungus.

Read ways of controlling mealy bugs and aphid attack on the plants.